The energy-saving effect and prediction method under various illuminance distribution types

This study employed the method of constant stimuli to obtain the equivalent illuminance and energy-saving effect of 14 illuminance distribution types. Among 14 types, the type T09 with only one luminary was the most energy-consuming, and T03 was the most energy-saving, the difference of their equivalent illuminances was 23%. When indoor illumination has the same average illuminance, but different Illuminance distribution, the overall indoor equivalent illuminance differs as well. When the illuminance distribution is more uniform, the equivalent illuminance is lower, and the perceived brightness is higher. This indicates that, at a fixed overall average illuminance of indoor space, or energy consumption of lighting, the illuminance redistribution can improve the brightness effectively. On the contrary, to maintain the equal brightness, illuminance distribution can be adjusted to lower the average illuminance, and reduce the energy consumption of lighting. Additionally, this study found that, symmetric luminary configuration usually leads to lower equivalent illuminance, and higher perceived brightness. This study further established a simple prediction equation for energy-saving effect of lighting. The above results indicated that, the illumination type of “one-room-one-light” commonly seen in houses may have latent energy waste. If adjusting it to “one-room-multiple-lights” illumination, then the uniformity ratio of illuminance can be improved, facilitating energy-saving of lighting.